get-latest-website

#!/bin/bash
set -e

get_modtime() {
  curl -qs https://hub.docker.com/v2/repositories/vandor2012/website/tags/ \
    | jq -r '.results | map(select(.name == "latest")) | .[0].last_updated'
}

datetime_to_unix() {
  date -d "$1" +%s
}

compare_dates() {
  # compare_dates now before minutes
  [[ $(("$2" - "$1")) -lt "$(( 60*$3 ))" ]]
  return $?
}

get_hash() {
  curl -qs https://hub.docker.com/v2/repositories/vandor2012/website/tags/ \
    | jq -r '.results | map(select(.name == "latest")) | .[0].images[0].digest'
}

current_date="$(datetime_to_unix $(get_modtime))"

if compare_dates "$current_date" "$(date +%s)" 5; then
  # less than 5 minutes
  echo "Last updated less than 5 minutes ago."
  exit 1
fi

old_hash="$(get_hash)"
echo "Old hash: $old_hash"

while [[ "$(get_hash)" = "$old_hash" ]]; do
  sleep 5
done
echo "New hash: $(get_hash)"